Straight-edge guide.



A. B. DARBYSON. STRAIGHT EDGE GUIDE. APPLIOATION IIILED MAR. 25, 1912.

Patented Nov. 12, 1912.

Inventor \X itnesses Attorneys \JULUMBIA PLANOGRAPH 60.. WASHINGTON, u. c.

ALLEN BURNIP DARBYSON, OF PHILIPSIBURG, QUEBEC, CANADA.

STRAIGHT-EDGE GUIDE.

- Specification of Letters Patent.

Patented Nov. 12,1912.

Application filed March 25, 1912. Serial No. 686,118.

To all whom it may concern;

Be it known-that I, ALLEN B. DARBYSON, a subject of the King of Great Britain, residing at Philipsburg, Province of Quebec, Canada, have invented certain new and useful Improvements in Straight-Edge Guides; and I do hereby declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention to be hereinafter described relates to a straight-edge or T square guide.

In order to more clearly disclosethe construction, operation, and use of the invention, reference should be had to the accompanying drawings forming part of the present application.

Throughout the several figures of the drawings like reference characters designate the same parts.

In the drawings: Figure 1 is a top plan of the invention, applied; Fig. 2 is a side view of one member; Fig. 3 is an end view of the same; Fig. 4 is a bottom plan view of the same; Fig. 5 is a top plan view of the invention applied to a T square; and Fig. 6 is a side view of the same.

The main objects of the invention are to provide a simple, efficient, durable, economical, and compact straight-edge or T square guide which may be readily and quickly applied.

Referring to the drawings in detail, 1 indicates a straight-edge such as is in common use by most draft-smen. A U shaped metal clip 2 embraces the edge of this stright-edge near each of its ends. The distance between the arms or branches of this clip is considerably greater than the thickness of the straight-edge. Embracing the upper arm of this clip is a somewhat similar clip 3. An adjusting screw 4 is passed freely through the upper arm of clip 3, threaded through the upper arm of clip 2, and bears against the lower arm of clip 3. The result of this construction is the movement of the arms of clip 2 toward or from the arms of clip 3, as the screw 4 is turned in one direction or the other. As the lower arm of clip 3 is forced toward the lower arm of clip 2, the straight-edge will be clamped securely between them.

The lower arm of the clip 2 is formed with a tail or extension 5 to which is pivotally connected the index point 6 of a bar or head 7. The under face of the tail or extension is provided with graduations which cooperate with the index needle or point. The pivotal connection acts as a center, and the cooperating graduations and index needle indicate the relative angular adjustments between the tail 5 and head 7. In order to secure the parts in adjusted positions, a threaded pin 8 and nut 9 are used. The pin projects from the tail and slides freely in an arcuate slot 10 in the base .of the point 6. By turning the nut down on the threaded pin, the parts may be positively bound or secured in any desired adjustment. The construction thus far described is duplicated for each end of the straightedge.

The head 7 for one end of'the straightedge is provided with a simple set of antifriction rollers 11 adapted to engage the edge of the drawing board and lessen the friction which would otherwise exist. The other head, is provided with sets of clamping clips 12 and 13, and cooperating screws 14, generally similar in construction, operation, and use to the clips 2 and 3, and bolts 4. Each clip 12 however, is provided with an off set flange 15 from which is supported a horizontal antifriction guide roller 16 adapted to engage the edge of the drawing board; as in the right hand portion of Fig. 1. Also, each of the clips 13 carries a small vertical antifriction guide roller 17 adapted to engage the top surface of the drawing board. The clips 12 and 13 with their screws 14, may be applied equally well either to the heads 7 or to the end of a straightedge. Figs. 5 and 6 show the latter application. When used as in Figs. 5 and 6, a guide bar or plate 18 should be provided on the drawing board. The thickness of the vertical wall of this bar or plate should be just equal to the distance between the edge of the horizontal guide wheel 16 and the adjacent face of the vertical guide roller 17. In this way, all relative lateral movement between the straight-edge of the guide bar will be prevented, and the movement of the straight-edge across the board will be kept perfectly true.

It is thought that the operation and use of the invention will be clear from the preceding detailed description.

Changes may be made in the construction, arrangement, and disposition of the several arts of the invention without in any way departing from the field and scope of the same, and it is meant to include all such Within this application wherein only preferred forms have been disclosed.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination, a straight-edge, two

' pairs of cooperating clips adapted to be clamped to the straight-edge near its opposite ends, one clip of each pair being provided with an extension having a set of graduations, heads provided with index points each having an arcuate slot, pivotal connections between each head and one of said extensions, antifriction devices carried by each head and adapted to engage the edge of a drawing board, a pin projectin from each of the aforesaid extensions and playing in each of said arcuate slots, and a binding nut threaded upon each pin.

2. In combination, a straight-edge, a pair of cooperating clips adapted to be clamped thereto, one. of said clips being provided with an extension having a set of graduations, a head provided with an index point, pivotal connections between said head and said extension, and antifriction devices carried by said head.

3. In combination, a straight-edge, a pair of cooperating clips adapted to be clamped so thereto, one of said clips being rovided With-an extension having a set 0 graduations, a head provided with an index point and having an arcuate slot, a pin projecting from the aforesaid extension and playing in said arcuate slot, a binding nut threaded upon said pin, pivotal connections between said head and said extension, and antifriction devices carried by said head.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

ALLEN BURNIP DARBYSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington. D. G. 

